MEMORANDUM
SUBJECT: Amended Record of Decision
McGraw-Edison Site
Centerville, Iowa
From: Bob Stewart, RPM
IANE/SUPR
Thru: Glenn Curtis, Chief
IANE/SUPR
TO:
Michael J. Sanderson, Director
SUPR Division
U.S. EPA Region VII
Attached for your signature is the Amended Record of Decision (ROD) for the
McGraw-Edison site in Centerville, Iowa. The action was chosen in accordance with
the Comprehensive Environmental Response, Compensation and Liability Act of 1980
(CERCLA), as amended by the Superfund amendments and Re-authorization Act of
1986 (SARA), 42 U.S.C. § 9601 et sea., and, to the extent practicable, the National Oil
and Hazardous Substances Pollution contingency Plan (NCP), 40 C.F.R. Part 300.
This decision is based on the Administrative Record for this site.
This Amended ROD presents the selected remedy to address groundwater
contamination at the site. The groundwater contains high levels of trichloroethylene,
which will be treated using an Iron Reactive Permeable Barrier and Natural Attenuation
A public hearing was held on May 18, 1999, to present the preferred remedy to
the public and to receive feedback regarding public acceptance of the remedy. Public
comments were supportive of the proposed plan. The Iowa Department of Natural
Resources is also supportive of the selected remedy.
If you have questions or concerns regarding the selected remedy, please call me
at extension 7654 or Glenn Curtis at extension 7726.
Attachments
REVISED:SUPR:IANE:STEWART:RHARRINGTON:X7875:A:MCGEDROD.706:07:16:99
IANE CNSL IANE
STEWART HOLMES CURTIS
Concurrences remain valid
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MEMORANDUM
SUBJECT: Amended Record of Decision
McGraw-Edison Site
Centerville, Iowa
From: Bob Stewart, RPM
IANE/SUPR
Thru: Glenn Curtis, Chief
IANE/SUPR
TO: Michael J. Sanderson, Director
SUPR Division
U.S. EPA Region VII
Attached for your signature is the Amended Record of Decision (ROD) for the
McGraw-Edison site in Centerville, Iowa. The action was chosen in accordance with
the Comprehensive Environmental Response, Compensation and Liability Act of 1980
(CERCLA), as amended by the Superfund amendments and Re-authorization Act of
1986 (SARA), 42 U.S.C. § 9601 et sea., and, to the extent practicable, the National Oil
and Hazardous Substances Pollution contingency Plan (NCP), 40 C.F.R. Part 300.
This decision is based on the Administrative Record for this site.
This Amended ROD presents the selected remedy to address groundwater
contamination at the site. The groundwater contains high levels of trichloroethylene,
which will be treated using an Iron Reactive Permeable Barrier and Natural Attenuation.
A public hearing was held on May 18, 1999, to present the preferred remedy to
the public and to receive feedback regarding public acceptance of the remedy. Public
comments were supportive of the proposed plan. The Iowa Department of Natural
Resources is also supportive of the selected remedy.
If you have questions or concerns regarding the selected remedy, please call me
at extension 7654 or Glenn Curtis at extension 7726.
Attachments
SUPR:IANE: STEWART:RHARRINGTON:X7875:A:MCGEDROD.706:07:09:99
SUPR
SANDERSON
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V*
*55B
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
X 1*01^ REGION VII
901 NORTH 5TH STREET
KANSAS CITY, KANSAS 66101
MEMORANDUM
SUBJECT: Amended Record of Decision
From:
Thru:
TO:
Attached for your signature is the Amended Record of Decision (ROD) for the
McGraw-Edison site in Centerville, Iowa. The action was chosen in accordance with
the Comprehensive Environmental Response, Compensation and Liability Act of 1980
(CERCLA), as amended by the Superfund amendments and Re-authorization Act of
1986 (SARA), 42 U.S.C. § 9601 et seq.. and, to the extent practicable, the National Oil
and Hazardous Substances Pollution contingency Plan (NCP), 40 C.F.R. Part 300.
This decision is based on the Administrative Record for this site.
This Amended ROD presents the selected remedy to address groundwater
contamination at the site. The groundwater contains high levels of trichloroethylene,
which will be treated using an Iron Reactive Permeable Barrier and Natural Attenuation.
A public hearing was held on May 18, 1999, to present the preferred remedy to
the public and to receive feedback regarding public acceptance of the remedy. Public
comments were supportive of the proposed plan. The Iowa Department of Natural
Resources is also supportive of the selected remedy.
If you have questions or concerns regarding the selected remedy, please call me
at extension 7654 or Glenn Curtis at extension 7726.
Attachments
McGraw-Edison Site
Centerville, Iowa
S4&UMut
Bob Stewart, RPM
IANE/SUPR
Glenn Curtis, Chief
IANE/SUPR
Michael J. Sanderson, Director
SUPR Division
U.S. EPA Region VII
RECYCLE@
MKft C0NTAHS RtCYClEb FSERS
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SUPERFUND AMENDMENT OF
THE RECORD OF DECISION
McGraw-Edison Site
Appanoose County
Centerville, Iowa
i'#v/ Michael J. Sanderson
¦J) Director
Superfund Division
U.S. EPA, Region VII
Date
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I \
PrC^
SUPERFUND AMENDMENT OF
THE RECORD OF DECISION
McGraw-Edison Site
Appanoose County
Centerville, Iowa
EPA
Region 7
JULY 1999
I. DECLARATION FOR THE AMENDED RECORD OF DECISION
Site Name and Location
The McGraw-Edison Site is located in a residential/industrial area on the southern edge
of Centerville, Iowa. Centerville is an industrial and agricultural center located in
Appanoose County in extreme south-central Iowa.
Statement of Basis and Purpose
This decision document presents the amended remedial action for the McGraw-Edison
Site in Centerville, Iowa, which was chosen by the United States Environmental
Protection Agency (EPA) in accordance with the Comprehensive Environmental
Response, Compensation and Liability Act of 1980 (CERCLA), as amended by the
Superfund Amendments and Reauthorization Act of 1986 (SARA), and, to the extent
practicable, the National Oil and Hazardous Substances Pollution Contingency Plan
(NCP), 40 C.F.R. Part 300. This decision is based on the administrative record for this
site. The state of Iowa concurs with the selected amendment to the remedy.
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2
Assessment of the Site
Actual or threatened releases of hazardous substances from this site, if not addressed
by implementing the response action selected in this Record of Decision (ROD)
Amendment, may present an imminent and substantial endangerment to public health,
welfare, or the environment.
Description of Selected Remedy
This ROD Amendment addresses contaminated ground water, using the revised
remedial alternative of Iron Reactive Permeable Barrier and Natural Attenuation
(IRPB/NA). The major components of the selected remedy include the following:
~ The installation, by hydrofracturing technology, of an IRPB to intercept the site
trichloroethylene contamination in the upper and intermediate sands.
~ The demonstration of NA at a rate to effectively remediate the remnant
contaminant plume.
~ Periodic and continued ground water monitoring to identify changes in ground
water quality.
Statutory Determinations
The selected remedy is protective of human health and the environment, complies with
federal and state requirements that are legally applicable or relevant and appropriate to
the remedial action, is cost-effective, and utilizes permanent solutions and alternative
treatment (or resource recovery) technologies to the maximum extent practicable. This
remedy also satisfies the statutory preference for remedies that employ treatment as a
principal element (i.e., reduce toxicity, mobility, or volume of contaminants through
treatment). Because hazardous substances above health-based levels are expected to
continue to be on-site in five years, a review will be conducted within five years after
commencement of remedial action to ensure that the remedy continues to provide
adequate protection of human health and the environment.
Data Certification Checklist
The following information is included in the Decision Summary section of the Amended
ROD. Additional information can be found in the Administrative Record for this site.
~ Contaminants of concern (COCs) and their respective concentrations.
~ Baseline risk represented by the COCs.
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3
~ Cleanup levels established for COCs and the basis for the levels.
~ Current and future land use assumptions from the baseline risk assessment.
~ Land use that will be available at the site as a result of the amended remedy.
~ Estimated capital, operation and maintenance (O&M), and total present worth
costs; discount rate; and the number of years over which the remedy cost estimates are
projected.
~ Decisive factors that lead to selecting the amended remedy.
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4
II. DECISION SUMMARY
1. INTRODUCTION
This ROD Amendment describes the revised remedial alternative for ground water
remediation for the McGraw-Edison Superfund site in Centerville, Iowa, and provides a
comparison with the previous preferred remedial alternative. A Vacuum Enhanced
Ground Water Recovery (VGR) system was selected as the approved ground water
remedy in an Explanation of Significant Difference (ESD) dated June 1994. However,
recent laboratory bench scale experiments and actual contaminated ground water
remediations at other sites indicate that other remedial options may achieve the
remedial action objectives of this project more quickly and cost-effectively than the
previously selected alternative of VGR. For these reasons the U.S. Environmental
Protection Agency (EPA) has selected a revised remedial alternative of Iron Reactive
Permeable Barrier and Natural Attenuation for remediation of the contaminated ground
water at the site.
The selected remedial action for contaminated soil at the site (soil vapor extraction) will
remain as previously approved.
This Amended ROD was developed by the EPA, as lead agency, with support from the
Iowa Department of Natural Resources (IDNR).
2. SITE BACKGROUND
The McGraw-Edison site is located on a 13-acre tract adjacent to Iowa Highway 5 in a
residential/industrial area on the southern edge of Centerville, Iowa. The McGraw-
Edison site is located approximately 1.5 miles southeast of downtown Centerville in an
industrial park. Centerville is located in extreme south-central Iowa. It is an industrial
and agricultural center. Access to Centerville is provided by highway and railway
systems.
The approximate legal description of the McGraw-Edison site is the SW 1/4 of the SW
1/4 of Section 6, Township 68 North, Range 17 West, in Appanoose County, Iowa, (See
Figure 1). The McGraw-Edison site refers to and includes all properties beneath which
ground water contaminated with trichloroethylene (TCE) has migrated. With the
exception of: Vinyl Chloride; 1,1-Dichloroethene; Trans-1,2-dichloroethene; Cis-1,2-
dichloroethene; and 1,1,2-Trichloroethane all of which are degradation products of
TCE, no other contamination of the ground water is known to exist. The approximate
extent of the McGraw-Edison site, based on available information, is presented as
Figure 2.
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5
McGraw-Edison manufactured toasters and toaster ovens at the site from 1965 to
1978. The manufacturing operations included nickel and chromium plating processes.
Rinse water associated with the plating operations was treated in the on-site
wastewater treatment plant. The manufacturing areas were housed in a structure
containing 194,800 square feet of floor space. The manufacturing building contained
concrete lined, below grade pipe chases and a 5,000 gallon above-ground solvent
storage tank. The pipe chases were located in the metal plating area and were used to
collect plating liquid and return it to the process vaults or the wastewater treatment
building. The solvent TCE was used in the manufacturing building to clean the metal
plating equipment. The treated wastewater was discharged to the Centerville sanitary
sewer system. The plating solids were discharged to drying beds located on the west
side of the wastewater treatment building.
McGraw-Edison Company sold the facility to Peabody International Corporation in
1980. Peabody rented the facility to a party who used the facility for storage of grain
and finished goods. Cooper Industries, Inc. purchased the stock of the McGraw-Edison
Company in 1985, and the McGraw-Edison Company became a wholly owned
subsidiary of Cooper Industries. In 1990, Cooper Industries bought the facility from
Peabody International.
Prior to the work on the soils and ground water, extensive removals were conducted on
the site to clean up hazardous waste releases in the drying beds, ponds, pipe chases,
building, and surface soil of the site. Cooper Industries is the Potentially Responsible
Party (PRP) for this site. They have participated in most of the cleanup activities that
have been accomplished to this point and are actively involved with the ground water
and source contamination remediation.
An EPA Unilateral Administrative Order (UAO) was issued to Cooper Industries by the
EPA on March 30, 1994. The Ground Water Operable Unit RI/FS [Remedial
Investigation and Feasibility Study] and the Supplemental RI/FS Investigation Report
characterized the site; identified the zones of contaminated soil and ground water;
assessed current and potential risks to the public health, welfare, and the environment;
established cleanup goals; identified and evaluated remedial action alternatives; and
presented the results of the aquifer pump tests. The initial ROD, dated September
1993, evaluated various soil and ground water remedial alternatives. Conventional
ground water pumping using ultraviolet catalyzed oxidation to treat the ground water
and in-situ treatment using soil vapor extraction (SVE) to treat the soils were the
recommended remedial actions prior to performing a treatability study. The post-ROD
evaluation provided an alternative to the selected ground water extraction process
option presented in the ROD based on the results of the RI/FS. The EPA issued an
Explanation of Significant Differences (ESD) to the ROD in June 1994. The ESD
presented VGR as an alternative technology to conventional pumping of ground water
at the site.
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The McGraw-Edison site is situated on a local topographic high area. Storm water from
the site is discharged to drainage ditches from drainage features located near the
northeast and southwest property corners. Surface water exiting the site from the
northeast corner flows eastward toward Hickory Creek and the Chariton River
(approximate distance of three miles). Surface water leaving the site through the
southwest culvert eventually flows westward into the upper and lower Centerville
reservoirs (approximate distance of one mile).
Three till units, which are separated in part by glacial deposits and demarcated by
historic soil horizons, have been identified at the site. The till units are referred to, from
bottom to top, as Till Unit 1, Till Unit 2, and Till Unit 3. Four sand units were
differentiated beneath the site designated from the bottom to top as the lower sand,
channel sand, intermediate sand, and upper sand. Uncorrelated, sporadic sand lenses
are also present within the till units.
The water-bearing unit or units transporting the TCE-contaminated ground water across
the site are the upper and intermediate sands which are encountered at depths from 20
to 40 feet below ground surface (bgs). The ground water level at the site is
approximately 30 feet bgs and flows east to west across the site. A perched ground
water table is present in the upper 2 to 3 feet of soil near the TCE storage area. Water
in this area recharges Till Unit 3 and the upper and intermediate sands. Monitoring well
MW-2 is screened within this perched unit. The volume of contamination is
undeterminable.
3. COMMUNITY PARTICIPATION
Public participation in the activities conducted thus far at this site have taken the forms
of request for comments on Proposed Plans, the ROD, and ESDs, plus holding public
meetings and visits with public officials to attempt to get as much input from the
community as possible. The Proposed Plan for this ROD Amendment was made
available to the public for a public comment period which began on May 10, 1999, and
ended on June 8, 1999. The proposed plan and other site-related documents were
available at the Drake Public Library in Centerville, Iowa, and at EPA Region VII in
Kansas City, Kansas. A public meeting was held during the public comment period at
the Centerville City Hall on May 18, 1999. At the meeting, the preferred remedial
alternative was presented, and public comments were received. Those comments,
which were the only public comments received during the comment period, are
addressed in the Responsiveness Summary section of this ROD Amendment.
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4. SUMMARY OF SITE RISK
A Human Health Risk Assessment of the McGraw-Edison site was performed by
Cooper Industries to assess the risks posed to human health and the environment by
the site. The purpose of a baseline risk assessment is to identify potential health risks
posed by the Chemicals of Concern (COC) present in the soil, ground water, surface
water, and sediments at this site associated with both current and future land uses
under the assumption of current (baseline) site conditions.
The risk assessment evaluated both current and future exposure situations. For
purposes of the risk assessment, it was assumed that no remedial action would be
performed at the site in order to conservatively evaluate the possible future risks posed
by the contamination. The following routes of exposure were evaluated: ingestion of
surface soils; dermal (skin) contact with surface soils; inhalation of surface soil particles
in air; inhalation of volatilized chemicals from soil to air; ingestion of ground water;
inhalation of volatilized chemicals in ground water; dermal contact with ground water;
ingestion of surface water; dermal contact with surface water; ingestion of sediments;
and dermal contact with sediments. These routes of exposure were evaluated for both
children and adults. It was assumed that these exposures would apply to adults and
children in residential settings, adult or child trespassers at the site, and to adult
workers in an occupational setting.
The risk assessment indicated that the McGraw-Edison site presented an unacceptable
risk to human health and the environment. The principal risk is from exposure to the
TCE-contaminated ground water. The carcinogenic risk by ingestion of ground water
for future on-site and off-site adult residents is six in ten thousand, which is expressed
using scientific notation as 6 x 10"4 and for future on-site and off-site child residents the
risk is four in ten thousand, or 4 x 10"4. The EPA considers risk above one in ten
thousand, or 1 x 10"4 unacceptable risk. The assessment was performed using EPA's
recommendations for Reasonable Maximum Exposure (RME) which is used to
conservatively estimate the highest current and future exposure that is reasonably
expected to occur.
In the realm of non-carcinogenic risk associated with the exposure pathways for COCs,
it has been determined that none are considered significant. Also, it has been
determined that the site does not pose a risk to the environment.
5. REMEDIAL ACTION OBJECTIVES
Remedial Action Objectives (RAOs) provide a general description of what the cleanup
will accomplish. The RAOs are most often general objectives such as prevention of
exposure to contaminants; prevention of plume migration; restoration of the ground
water to drinking water quality, etc. These objectives are based on available
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information and standards such as Applicable or Relevant and Appropriate
Requirements (ARARs) of other environmental laws, and risk-based levels established
in the risk assessment. For this undertaking the RAOs are restoring the aquifer to
beneficial use as a practical supply of drinking water.
For the TCE-contaminated ground water, EPA considers a cleanup level of five
micrograms per liter (5 ,ag/L) to be protective of human health based on the Maximum
Contaminant Level (MCL) of 5 ^g/L for TCE in drinking water. This is the objective for
this clean up.
6. SUMMARY OF REMEDIAL ALTERNATIVES
The CERCLA requires that the selected site alternative be protective of human health
and the environment; be cost effective; comply with other statutory laws; utilize
permanent solutions; and, to the maximum extent practicable, employ alternative
treatment technologies and resource recovery selections. In addition, the statute
includes a preference for the use of treatment as a principal element for the reduction of
toxicity, mobility, or volume of the hazardous substances.
The Ground Water Operable Unit Post Record of Decision Supplemental FS Report
dated June 1993 evaluates in detail the previous and proposed remedial alternatives for
addressing the contaminated ground water plume at this site.
Previously Selected Ground Water Alternative: Vacuum Enhanced Ground Water
Recovery (VGR)
Capital Cost: $1,150,000
Present Worth of Annual O&M Cost: $1,055,000
Total Present Worth Cost: $2,205,000
Clean up time: 15 to 30 years
The VGR includes ground water monitoring, extraction of contaminated ground water
using vacuum enhanced extraction wells, on-site ground water treatment using filtration
and Granular Activated Carbon (GAC), and discharge to the surface water or the
Centerville Publicly Owned Treatment Works (POTW).
The VGR extraction wells would be located in three areas: a contamination source in
the vicinity of the manufacturing building; a plume containment area downgradient of
the source and southeast of the site; and the south culvert area. The VGR system
would consist of closely spaced extraction points connected by individual pipes to a
vacuum manifold. The vacuum is obtained by using a positive displacement blower.
The level of vacuum which the blower can achieve and maintain affects the depth to
which the ground water can be drawn through the VGR extraction points and thereby
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the amount of water that can be recovered from the water-bearing formation. Two or
more lifting stages would be used in each VGR point construction to increase the
working depth of the system. The ground water is brought above grade into a manifold
and is accumulated in a surge tank prior to being treated.
The extraction system would be designed to operate on a continuous basis. Extraction
wells would be located in the upper and intermediate sand units. The estimated
average continuous flow rate from each well is one gallon per minute (gpm) with a
maximum estimated total flow of 200 gpm. The discharge from each well would be
connected to a below ground piping system which would transfer ground water to an
on-site treatment system.
Soil excavated during trenching activities for the system's installation would be tested to
determine if contaminated. If so, it would be treated on-site in a stockpile. This
stockpile would be constructed in the former parking area to the east of the
manufacturing building. The stockpile would consist of contaminated soil and be
enclosed (top, sides, ends, and bottom) by polyethylene sheeting. Horizontal SVE
points would be constructed within the soil pile and these would be used to induce air
flow through the soil in order to remove TCE. These points would be connected to the
manifold of the SVE system which will be in service treating the off-gas flows from the
contaminated soils on site.
The treatment system in the building would be used to treat extracted ground water
from the contaminant source at the manufacturing building area and the south culvert
outfall area. Ground water extracted from the remedial systems would be transferred to
a single surge tank in the equipment building. Ground water would be pretreated to
remove inorganic precipitates using bag filters. The GAC would be used to remove the
dissolved TCE in accordance with the ROD and ESD. Two GAC units would be used in
series to ensure removal of TCE prior to discharge of the water. The system was
designed to accept the expected ground water flow rates and anticipated TCE
concentrations from the two areas. Treated ground water would be discharged to a
surface water outfall. Water generated during backwashing of the pretreatment system
would be discharged to the city of Centerville POTW.
The second ground water treatment system, which would be installed in the
downgradient ground water plume area, would consist of a similar design but on a
smaller scale. The expected flow rates and concentrations in this water stream would
be lower than those for the system described above. Ground water extracted via the
VGR system would be sent to a surge tank and then through a pretreatment system.
The pretreatment system would consist of a particle bag filtration system. Ground
water would then be passed through two GAC vessels. Treated ground water would be
pumped to the same discharge National Pollutant Discharge Elimination System
(NPDES) outfall point used for discharge of the water from the contaminant source area
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building system. The pretreatment filtration system would not be capable of
backwashing. Filters would be changed-out manually when necessary. Soils produced
by the system's construction would be stockpiled and treated as noted above.
Discharge of the treated ground water would be in compliance with all local, state, and
federal regulations. Treated ground water would be discharged to the city of Centerville
POTW or to an NPDES outfall. If this discharge is sent to a POTW, the contractor
would be required to meet all pre-treatment and has specific agreement from that
facility to accept this waste. The NPDES section of the IDNR regulations requires
permitting for water discharge to the surface water and some sanitary sewer systems.
However, according to CERCLA, permits do not have to be obtained for remedial
actions conducted within the Superfund site perimeters, per CERCLA 121(e)(1). Even
though the permit is not required, the design of the remedial systems would comply with
the substantive requirements of an applicable NPDES agreement.
The treatment system would be automated so that a full-time operator would not be
required. Routine inspections would be required on a weekly basis. Controls would be
provided to automatically shut down the extraction wells if a system mechanical failure
occurred.
Soil particles filtered from the influent ground water would be analyzed after initial
operation of the plant for hazardous waste characteristics. The filtered soils would then
be disposed of at an appropriate landfill. Spent GAC would be reactivated for
continued use or it would be disposed of at an appropriate treatment, storage, and
disposal facility. Reactivation of spent carbon was assumed for cost estimating
purposes.
This alternative includes periodic and continued ground water monitoring to identify
changes in contaminant concentrations and to evaluate the effectiveness of the
extraction and treatment system. Monthly monitoring of ground water from the
monitoring wells would be performed initially to ensure the VGR system is capturing the
contaminated plume. Monitoring of discharges to the POTW and to the drainage ditch
would be performed on a monthly basis. Treated water would be analyzed for VOCs
and other parameters required by the discharge agreement (e.g., pH, total suspended
solids, biochemical oxygen demand).
Iron Reactive Permeable Barrier and Natural Attenuation Alternative (IRPB/NA)
Capital Cost: $805,000
Present Worth of Annual O&M Costs: $133,000
Total Present Worth Cost: $938,000
Clean up time: 10 years
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This ground water remedial alternative involves the installation, by hydrofracturing
technology, of an IRPB to intercept the site TCE contamination in the upper and
intermediate sands and the demonstration of natural attenuation at a rate to effectively
remediate the remnant contaminant plume. Hydrofracturing is a method developed in
the petroleum industry, that allows placement of the chemically reactive iron material in
a controlled manner into the subsurface to form the trench.
Vertically oriented hydraulic fracturing technology requires an injection delivery system
comprised of three prime components: 1) the fracture initiation device; 2) the controlled
pumping equipment; and 3) the real time monitoring and mathematical calculations for
determining fracture geometry. The fracture initiation device controls the fracture
orientation. The pumping system is specially designed to achieve a precise control of
fracture fluid pressures and flow rates. The real time monitoring system provides
feedback response to ensure the fractures are propagating as planned. The in-hole
initiation tools comprise a suite of tools depending on the geological formation, depth
and the fracturing fluid required for the particular application.
The IRPB would reduce the VOCs encountered in the site ground water to less than
drinking water Maximum Contaminant Levels (MCL), and the VOC concentrations in the
remnant plume downgradientfrom the IRPB source control reactive barrier would
decline with time to less than MCLs by natural attenuation processes. The
contamination upgradient of the IRPB would experience some lessening due to natural
attenuation but this would not be effective enough to meet the Remedial Action
Objectives. The proposed location of the IRPB with respect to the TCE plume is shown
on Figure 8. A cross section along the IRPB is shown on Figure 9.
The IRPB would have a 3 inch average thickness, a vertical height of 20 feet high and
horizontal length of 240 feet. It would extend from an approximate elevation of 995 feet
above mean sea level (ft-msl) down to an elevation of 975 ft-msl (25 ft to 45 ft bgs)
covering a cross section area of 4,800 square feet. The IRPB would be constructed by
hydraulically fracturing only the sand units shown in the cross-section on Figure 9. The
fracturing wells would be able to fracture individual sand units, if necessary. The
overlying and underlying tills are sufficient to contain the fractures within the sand unit
and thus maximize the thickness of the reactive barrier.
The IRPB would be located approximately 70 feet downgradient from ground water
monitoring well MW-3A and 35 feet upgradient from monitoring well EW-1 (see Figure
8). The IRPB is intended to intercept the contaminated ground water flowing in the
direction of the TCE plume through the upper and intermediate sand units encountered
at the site. The location of the IRPB shown on Figure 8 is an optimum layout for a
source control reactive barrier.
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The IRPB would be constructed by injecting chemically reactive iron mixtures through
multiple well heads which would be typically spaced 15 feet apart along the permeable
barrier alignment. Generally two well heads are initiated and injected simultaneously to
achieve a coalesced continuous fracture filled with the iron reactive mixture. The next
pair of simultaneously injected well heads are spatially located to ensure the
neighboring fractures overlap sufficiently to provide a continuous permeable treatment
barrier. The quantities of injected iron reactive mixture are continuously monitored to
ensure sufficient reactive iron is injected through the individual well heads.
Strict quality control procedures would be implemented during construction of the IRPB
to provide the necessary assurance that the reactive barrier system's design
¦" performance requirements are achieved. Construction quality control procedures and
acceptance criteria include the following:
~ Consistency tests of the iron reactive mixture
~ Thickness and injected quantities of reactive iron in the various hydrogeologic
units
~ Tests to determine that the reactive wall is properly installed during injection
~ Effectiveness of the wall from hydraulic pulse tests
The permeable reactive wall would be tested for its hydraulic effectiveness by pulse
interference tests. Pulse interference tests involve a cycle injection of fluid into the
source well. High precision measurement of the pressure pulse in a neighboring well
will give a detailed hydraulic characterization between the wells.
After construction, the IRPB would consist of a wall, at least as permeable as the
natural formation, of granular iron filings. The iron filings serve as the catalyst in a
chemical process which causes the VOCs in the contaminated ground water which
pass unimpeded through the IRPB to be reductively dechlorinated to the non-toxic
products of ethene and ethane.
This alternative includes periodic and continued ground water monitoring to identify
changes in ground water quality up and downgradient of the IRPB in order to evaluate
the effectiveness of the reactive barrier. Quarterly monitoring of ground water from the
IRPB performance monitoring wells would be performed to ensure the IRPB system is
functioning satisfactorily over the first two years after installation and semi-annually
during years 3 and 4. Thereafter, these IRPB performance wells would be monitored
yearly.
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The natural attenuation studies at this site of time trend analysis, natural attenuation
indicator parameters, a scoring system, analytical fate and transport modeling, and site
specific modeling with sensitivity categorization show noticeable declines in TCE
conditions in the aquifer (see Supplemental Data Collection and Evaluation of
Alternative Ground Water Remedy [Iron Reactive Permeable Barrier and Natural
Attenuation] by Golder Sierra dated October 23, 1998, and Revised Report on Ground
Water Operable Unit Post Record of Decision Supplemental Feasibility Study McGraw
Edison Superfund Site Centerville, Iowa, by Golder Sierra dated March 19,1999).
These analyses and modeling show that a complete degradation from TCE to ethene is
occurring on-site and indicate that active bioremediation of TCE accounts for at least 80
percent of this degradation. Further, the estimated rate of this degradation does not
endanger any receptors during the period required to obtain the project objectives.
Therefore, natural attenuation is incorporated into this alternative for that area of the
plume beyond the IRPB.
Detailed site-wide ground water monitoring (including VOCs and natural attenuation
parameters) would be conducted semi-annually for the first four years to assure that
natural attenuation mechanisms remain active and effective at the site. The EPA's
Technical Protocol for Evaluating Natural Attenuation of Chlorinated Solvents in Ground
Water. EPA/600/R-98/128, September 1998, will be used to prove natural attenuation's
success. If successful, site-wide ground water monitoring for VOCs would be continued
once a year.
Dual Iron Reactive Permeable Barrier Alternative (Dual IRPB)
Capital Cost: $1,610,000
Present Worth of Annual O&M Costs: $116,000
Total Present Worth Cost: $1,726,000
Clean up time: 10 to 15 years
The Dual IRPB Alternative involves the installation by hydrofracturing technology of an
IRPB at the source area to intercept the site TCE contamination in the upper and
intermediate sands and a second IRPB for plume remediation as shown on Figure 10.
The primary IRPB would reduce the VOCs in ground water encountered in the site
source area to less than MCLs as detailed above. The VOC concentrations in the
remnant plume, downgradient from the IRPB source control reactive barrier, would be
anticipated to decline with time to less than MCLs by natural attenuation. However, if
natural attenuation varies significantly from the predictions of the site-specific model
while taking into consideration the sensitivity characterization during the first four years
of monitoring, the second IRPB for plume remediation would be installed. Installation
and construction monitoring of the two IRPBs would be as discussed under the
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previous IRPB alternative. The proposed location of the IRPBs with respect to the TCE
plume is shown on Figure 10. A cross section along the source control IRPB is shown
on Figure 9.
This remedy includes periodic and continued ground water monitoring to identify
changes in contaminant concentrations up and downgradient of the IRPB in order to
evaluate the effectiveness of the reactive barriers. Quarterly monitoring of ground
water from the IRPB performance monitoring wells would be performed to ensure the
IRPB system is functioning satisfactorily over the first two years after installation and
semi-annually during years three and four. Thereafter, the IRPB performance wells
would be monitored yearly.
7. ANALYSIS OF APPLICABLE OR RELEVANT AND APPROPRIATE
REQUIREMENTS (ARARs)
Section 121(d) (2) of CERCLA, 42 U.S.C. §9621 (d) (2), requires that clean up actions
conducted under CERCLA achieve a degree or level of cleanup which, at a minimum,
attains "any standard, requirement, criteria or limitation under any federal environmental
law...or any promulgated standard, requirement, criteria, or limitation under a state
environment or facility siting law that is more stringent than any federal standard
...(which) is legally applicable to the hazardous substance or pollutant or contaminant
concerned or is relevant and appropriate under the circumstances of the release or
threatened release of such hazardous substance or pollutant of contaminant..." The
identified standards, requirements, criteria, or limitations thus adopted from other
environmental laws, which govern on-site cleanup activities at this site, are referred to
as ARARs.
For on-site cleanup activities, under Section 121(e)(1) of CERCLA, EPA is not required
to obtain any federal, state, or local permits for actions conducted on-site, complying
only with the substantive (non-administrative) requirements of the identified federal and
state laws. On the other hand, for cleanup activities that will occur off-site, both the
substantive and the administrative requirements of such laws will apply.
This section identifies the ARARs for the Ground Water Alternatives which will apply to
the on-site cleanup activities for this site. (Laws and regulations which apply to off-site
cleanup or disposal activities are not called "ARARs" and are not enumerated here.)
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FEDERAL ARARs
Clean Water Act of 1977, as amended (33 U.S.C. §§1251-1376)
40 CFR Parts 122-125
The National Pollutant Discharge Elimination System (NPDES) was established to
control discharge of pollutants from any point source into waters of the United States.
A permit will not be required since the site is being remediated as part of the Superfund
program and the discharge point is on-site; however, the substantive requirements of
the regulations must be met. These regulations apply to the discharge of treated
ground water and process water to surface water.
Discharge limits will be established during remedial design and will be consistent with
the requirements of the NPDES program. If established surface water discharge limits
are not met, provisions for alternate effluent limits can be found in this part.
Under the Clean Water Act, states must establish ambient water quality criteria for the
protection of surface water based on use classifications and the criteria stated under
Section 304(a) of the Clean Water Act. These criteria are applicable (see the
discussion under "State ARARs," below) and will be used to establish discharge limits
for treated ground water and process water.
Safe Drinking Water Act of 1986, as amended (40 U.S.C. §§300 et sea.)
40 CFR Part 141
Primary Drinking Water Standards are established by this part. The Safe Drinking
Water Act's Maximum Contaminant Levels (MCL) are health-based standards for
chemicals that may be found in public water supplies. The MCL for TCE would be
applicable if the treated water is beneficially reused for human consumption.
The discharge of treated ground water or process water will otherwise not affect
drinking water in a public water supply directly. However, the potential for residual
contaminants percolating to ground water exists. The National Oil and Hazardous
Substances Pollution Contingency Plan (NCP) requires consideration of MCLs, where
they exist, as relevant and appropriate to ground water cleanup standards when the
aquifer is a current or potential source of drinking water. The MCL for TCE is relevant
and appropriate for establishing cleanup standards to be met during implementation of
the remedy.
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Resource Conservation and Recovery Act (RCRA) of 1976, as amended (42 U.S.C.
§§6901-6987)
40 CFR Part 261
The criteria set forth in this part will be used to determine if solid wastes excavated,
created through treatment or otherwise generated during the implementation of the
remedy are hazardous or non-hazardous.
40 CFR Part 262:11
The methods for determining whether a solid waste is hazardous are set forth in this
part. All generators of solid wastes are required to determine if a waste is hazardous.
Wastes determined to be hazardous will be managed in accordance with the rules
applicable to hazardous wastes.
40 CFR Part 262.34
The accumulation of hazardous wastes on-site is addressed by this part. In the event
any of the solid wastes excavated, created through treatment or otherwise generated
during the implementation of the remedy are hazardous, these regulations will apply.
No excavations of hazardous wastes shall be allowed on-site for a period of 90 days.
The RCRA regulations that apply to facilities for the treatment, storage or disposal of
hazardous waste were determined not to be applicable or relevant and appropriate to
the alternatives developed for this site.
Hazardous Waste Operations and Emergency Response, Final Rule
29 CFR 1919.120
This rule applies to the remedial activities.
National Ambient Air Quality Standards
40 CFR Parts 50. 53. and 61
These standards would be applicable for controlling fugitive emissions. This standard
would apply primarily to the previously selected alternative.
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STATE ARARs
Iowa Environmental Quality Act (Iowa Code 133)
This Act empowers the IDNR to establish regulations and programs similar to the
federal Safe Drinking Water Act and the Clean Water Act. Applicable state regulations
include the Iowa Drinking Water Rules and the Iowa Water Pollution Control
Regulations.
Iowa Ground Water Protection Act
This Act establishes a state goal to prevent contamination of ground water.
Iowa Air Pollution Control Regulations
These establish rigorous emission standards for hazardous air contaminants, which
would primarily apply to the previously selected alternative.
8. EVALUATION of ALTERNATIVES
During the detailed evaluation of remedial alternatives, each alternative is assessed
against nine evaluation criteria. These criteria are: overall protection of human health
and the environment; compliance with applicable or relevant and appropriate require-
ments; long-term effectiveness and permanence; reduction of toxicity, mobility, or
volume; short-term effectiveness; implementability; cost; and state and community
acceptance.
The evaluation criteria are described below:
Overall protection of human health and the environment addresses whether or
not a remedy provides adequate protection and describes how risks posed through
each exposure pathway are eliminated, reduced or controlled through treatment, engi-
neering controls or institutional controls.
Compliance with applicable or relevant and appropriate requirements (ARARs)
addresses whether or not a remedy will meet all of the applicable or relevant and
appropriate requirements of other federal and state environmental statutes and
requirements or provide grounds for invoking a waiver.
Long-term effectiveness and permanence refers to the ability of a remedy to
maintain reliable protection of human health and the environment over time, once
cleanup goals have been met.
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Reduction of toxicity, mobility, or volume through treatment is the anticipated
performance of the treatment technologies a remedy may employ.
Short-term effectiveness addresses the period of time needed to achieve
protection and any adverse impacts on human health and the environment that may be
posed during the construction and implementation period until cleanup goals are
achieved.
Implementabilitv is the technical and administrative feasibility of a remedy
including the availability of materials.and services needed to implement a particular
option.
Cost includes estimated capital and operation and maintenance costs and net
present worth costs.
State acceptance indicates whether, based on its review of the RI/FS reports and
Proposed Plan, the state concurs, opposes, or has no comment on the preferred
alternative at the present time.
Community acceptance indicates whether the community concurs, opposes or
has no comment on the preferred alternative, and is judged by public comments
received at the public meeting, during the public comment process, or by other means.
The following comparative analysis presents the strengths and weaknesses of the
alternatives relative to each other with respect to each of the nine criteria, and how
reasonable variations of key uncertainties could change the expectations of their
relative performance. Under each individual criterion, the alternative(s) that performs
the best overall in that category is discussed first with other alternatives discussed in
the relative order in which they perform.
Overall Protection of Human Health and Environment
The IRPB/NA Alternative and the Dual IRPB Alternative would protect human health
and the environment from the risks posed by contaminated ground water at the site
through in-situ reductive dechlorination of TCE contaminated ground water to the
non-toxic end products. The passive treatment of ground water by the IRPBs and
Natural Attenuation would reduce the toxicity, mobility, and volume of the contaminants
present in the ground water. The VOCs are destroyed by reductive dechlorination in
the presence of granular iron by turning the chlorides into ethene and ethane through
natural attenuation, i.e., biodegradation. The reduction of organic contaminants by the
IRPB would reduce the risks to human health and the environment by removing
contaminants from ground water at the site.
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The VGR Alternative would provide protection of human health and the environment
through ground water extraction and treatment. Extraction at an estimated total rate of
200 gallons per minute would actively remove organic chemicals, such as TCE, from
the intermediate and upper sands and minimize the potential for off-site migration of
contamination. Treatment of VOCs in ground water to meet discharge criteria would
further reduce the risks to human health and the environment. Treatment residuals
from the treatment process would potentially pose continued risks to human health and
the environment. Spent GAC and pretreatment filtration residues would continue to
pose minor risks if the residuals are disposed of in a controlled landfill.
Compliance with ARARs
All alternatives would comply with all state and federal action-specific ARARs and are
anticipated to comply with all chemical specific ARARs.
Long-Term Effectiveness and Permanence
Long-term residual risks between the VGR Alternative, the IRPB/NA Alternative, and
the Dual IRPB Alternative differ. The IRPB/NA Alternative is expected to be effective
and permanent at meeting remedial action objectives in approximately 10 years. The
Dual IRPB Alternative is expected to be effective and permanent at meeting remedial
action objectives in approximately 10 to 15 years due to much longer distances
between the contaminants beginning locations and the second IRPB. Long-term
management requirements are minimal for the IRPB/NA and Dual IRPB Alternatives.
While all remedies would require continual ground water monitoring, the IRPB/NA
Alternative would require additional ground water monitoring to demonstrate that
natural attenuation is ongoing.
The VGR Alternative includes ground water extraction which is expected to be effective
and permanent at meeting remedial action objectives in approximately 15 to 30 years.
Ground water extraction would be effective at lowering ground water TCE
concentrations in the intermediate and upper sands in the active zones of extraction
and at reducing the potential for off-site migration of contaminants from these units.
The VGR remedy includes treatment of the extracted ground water which would require
long-term management including monitoring and maintenance. Treatment of ground
water using GAC, as proposed in the VGR Alternative, may pose long-term residual
risks due to the disposal of the spent GAC and pretreatment residues or due to thermal
reactivation of spent GAC.
Ground water monitoring including natural attenuation considerations, which is required
in all of the comparative remedies, would provide a mechanism for evaluation of long-
term effectiveness and permanence of the process options proposed under each
alternative.
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Reduction of Toxicity, Mobility, and Volume Through Treatment
The IRPB Alternatives break down TCE contamination in the ground water to the
non-toxic daughter products of ethene and ethane. These two remedies reduce the
toxicity, mobility and volume of the TCE and cis-1,2-DCE contaminants in the ground
water. The IRPB/NA Alternative relies on natural attenuation to reduce the VOCs in the
remnant contaminated plume downgradient of the IRPB.
The VGR remedy includes ground water treatment that would reduce by varying
degrees the toxicity, mobility, or volume of contaminants in the ground water. The GAC
is a treatment technology that removes VOCs from the aqueous phase but does not
destroy VOCs. The VOCs are destroyed when the liquid phase activated carbon is
regenerated. The reduction of contamination would greatly depend on the recovery of
contaminated ground water by the VGR system.
Short-Term Effectiveness
Short-term risks to the community and site workers are minimal under the two passive
remedies, IRPB/NA and Dual IRPBs, and only slight for the VGR Alternative. Potential
risks to on-site workers who may come in contact with contaminated ground water or
soils during construction and sampling activities would be minimized through
compliance with all applicable Occupational Safety and Health Administration
regulations.
None of the ground water alternatives are expected to meet remedial action objectives
in the short-term. The time to meet target cleanup levels in ground water by the
IRPB/NA Alternative is estimated by the site specific modeling to be 10 years. The time
to meet target cleanup levels in ground water by extraction of contaminated ground
water from the intermediate and upper sand units under the VGR Alternative could
range from 15 to 30 years according to ground water extraction rates measured during
the treatability study.
Implementabilitv
Overall, about equal difficulty and uncertainty is expected regarding the technical and
administrative feasibility of VGR and the two passive IRPB alternatives. While natural
attenuation is a very straightforward and basic system whose main element in
construction and operation is placing and using an effective monitoring program, IRPB
is a cutting edge technology which does not yet have the track record of the established
technologies but does have an impressive short-term record on these points. The VGR
is new also, but has a much wider use and performance record although, on this
undertaking, it will be a much more physically demanding effort.
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The VGR and IRPB design and installation both require technical specialists. It is
judged that the IRPB systems are somewhat more difficult to install but much easier to
operate. The filtered waste stream in the VGR remedy would be expected to meet the
POTW or the NPDES discharge requirements for inorganic contaminants. Ground
water monitoring would be easily implemented under each of the ground water
alternatives.
Cost
A cost comparison for the ground water alternatives include the detailed cost estimates
for each alternative.
The total present worth of the IRPB/NA Alternative would be the lowest at a cost of
$938,000. The total present worth cost of the VGR Alternative would be the greatest at
a cost of $2,205,000. The total present worth cost of Dual IRPB Alternative is
$1,726,000.
State and Community Acceptance
Both IDNR and the public have been receptive to all of EPA's lead actions on this
project. Their concerns and comments have been considered in all past decisions and
were considered in this ROD Amendment. The IDNR has submitted a letter to EPA
indicating that it accepts the preferred alternative of IRPB/NA. The public also indicated
its acceptance of the preferred alternative during the public meeting of May 18, 1999.
This topic is discussed in more detail in the Responsiveness Summary.
9. SELECTED REMEDY
The EPA's new Selected Remedy for ground water remediation at the McGraw-Edison
Site is the IRPB/NA Alternative with the Dual IRPB Alternative as an initial Contingency
Remedy and VGR Alternative as a secondary Contingency Remedy.
The EPA believes at the present time that the IRPB/NA Ground Water Alternative will
provide the best solution among alternatives with respect to the evaluating criteria. The
IRPB/NA alternative achieves the clean up goals in an estimated time of 10 years. It
also does so more efficiently than the other two alternatives. By comparison, it is
expected that the VGR Alternative would reach the cleanup standards in approximately
15 to 30 years and the Dual IRPB Alternative would take approximately 10 to 15 years.
A quicker remediation time will provide added protection to human health and the
environment. Compliance with ARARs, short-term effectiveness, and implementability
would be similar for the IRPB/NA Alternative as with the VGR Alternative and the Dual
IRPB Alternative. The removal of contaminants by the IRPB would be advantageous
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over the VGR Alternative which would have residuals for disposal and management.
The total estimated present worth cost for the IRPB/NA is the lowest.
Detailed site-wide ground water monitoring (including VOCs and natural attenuation
parameters) will be conducted semi-annually for the first four years to assure that
natural attenuation mechanisms remain active at the site. If after four years, it is
determined that natural attenuation mechanisms are no longer sufficiently active to
achieve the ground water remediation goals in a reasonable time frame, then the Dual
IRPB Alternative will be implemented. The second IRPB will be monitored quarterly for
the first 2 years and semi-annually during years 3 and 4 after construction to assure
that it is functioning satisfactorily. Thereafter, site-wide ground water monitoring for
VOCs will be conducted once a year.
Results of ground water monitoring will also be used to evaluate the effectiveness of
the IRPBs. If it becomes apparent that the ground water cleanup level of 5 ^g/L will not
be reached within eight years, the VGR Alternative will be implemented.
10. COMMUNITY ROLE IN SELECTION PROCESS
The EPA and IDNR rely on public input to ensure that the concerns of the community
are considered in selecting an effective remedy for each Superfund site. To this end,
the Supplemental Data Collection and Evaluation of Alternative Ground Water Remedy
Report, the Ground Water Operable Unit Post Record of Decision Supplemental
Feasibility Study Report, and supporting documentation were made available to the
public for a public comment period which began on May 10, 1999, and concluded on
June 9, 1999.
A public meeting was held during the public comment period at Centerville, Iowa, on
May 18, 1999, to present the conclusions of the supplemental investigation, to elabo-
rate further on the reasons for revising the preferred remedial alternative, and to receive
public comments. Comments received at the public meeting have been addressed in
the Responsiveness Summary Section of this amended ROD.
11. STATUTORY DETERMINATIONS
Under CERCLA Section 121, EPA must select remedies that are protective of human
health and the environment, comply with applicable or relevant and appropriate
requirements (unless a statutory waiver is justified), are cost-effective, and utilize
permanent solutions and alternative treatment technologies or resource recovery
technologies to the maximum extent practicable. In addition, CERCLA includes a
preference for remedies that employ treatment that permanently and significantly
reduces the volume, toxicity, or mobility of hazardous wastes as a principal element.
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The EPA believes that this Selected Remedy will be protective of human health and the
environment, will comply with ARARs, will be cost effective, and will utilize permanent
solutions and alternative treatment technologies or resource recovery technologies to
the maximum extent practicable. The remedy also will meet the statutory preference for
the use of treatment as a principal element. The reasons for these conclusions are
discussed in Section 8 EVALUATION of ALTERNATIVES above. The selected remedy
has not been significantly changed from the preferred alternative presented in the
Proposed Plan.
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III. RESPONSIVENESS SUMMARY TO COMMENTS FROM PUBLIC
MEETING
Comment 1: A commenter asked about the possibility of contaminant migration to the
north.
Response 1: The EPA has seen no indication that migration is occurring to the north.
The predominant flow is to the southeast, based on all the ground water
monitoring we have done. Additional monitoring will be done in the future,
during remediation, to make sure migration in other directions is not taking
place. Additional monitoring wells will also be installed to better monitor
the site.
Comment 2: A commenter asked if the natural attenuation would take place in the far
reaches of the plume.
Response 2: The EPA expects that natural attenuation is taking place and will continue
to take place in the plume, especially since the permeable barrier will
reduce the highest levels of contamination in the plume, those nearest the
source.
Comment 3: Another commenter asked whether the site owner could now sell some of
the property, or use it for their own manufacturing.
Response 3: Portions of the site that have been cleaned up would be suitable for use
by the company. Since the building cleanup is complete, the building
could be used in a manner consistent with remaining levels of
contamination. The land surface is also suitable for reuse; EPA's primary
remaining concerns are with the groundwater. If any of the property was
sold, any use restrictions currently placed on the property would have to
be passed on to the new property owner. No drinking water or irrigation
wells should be placed on the site.
Comment 4: A member of the Appanoose County Board asked about the status of an
access agreement with the county for some work next to the building. He
also asked when work would begin on the site.
Response 4: Cooper Industries is very anxious to begin the work, and would likely have
construction completed by late fall 1999. Regarding access to the county
land, the McGraw-Edison site is adjacent to the county property. The
plume of contaminated ground water runs beneath the property boundary,
under the county property, and a large part of the permeable barrier will
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be under county property. During the period of permeable barrier
construction, the property could not be used. After construction is
complete, however, some uses of the land surface could be appropriate.
There will also be a very small amount of soil cleanup right at the fence
line on county property.
Comment 5: The same commenter asked about the probable length of time that the
preferred remedy will take to meet the cleanup levels.
Response 5: The EPA estimates that the system will need to be in place for 7-13 years,
with an average duration of 10 years expected.
Comment 6: The same commenter asked about the impact of this site remediation to
another piece of county property to the east. This property is 204 feet, 10
inches long and 25 feet wide.
Response 6: Based on EPA's current knowledge of the site conditions and the work to
be performed, it is unlikely that the property in question will be affected by
the remediation work.
Comment 7: The Centerville City Mayor asked if Cooper Corporation would pay the
expenses of the cleanup, and if there is any limit to their responsibility.
Response 7: Cooper is responsible for implementing the remedial action, both for the
soil and ground water. The EPA will oversee the design and cleanup.
Cooper is responsible under an order with EPA to do the cleanup,
regardless of whether the property is sold or not.
Comment 8: The Mayor also asked if portions of the building could be used now. He
also asked if the building could be sold or donated to the city.
Response 8: The building is clean, but there are two small areas that are planned to be
used during the cleanup. The plan is to use an area in the southwest
corner to house equipment used with the soil vapor extraction remedy.
There is also a small area under the southeast corner of the building that
requires remediation by the soil vapor extraction system. This will require
that wells be installed inside the building. So most of the 267,000 square
feet inside the building could be used immediately. With regard to selling
the building, the company could sell it, but the new purchaser may be
exposing themselves to some liability. The EPA is interested in economic
development of properties such as this, and would certainly work with
anyone interested in reusing the property. If the city were to receive the
property as a donation, EPA would also be interested in working with the
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access, and did not make the problem worse, EPA could negotiate an
agreement with the prospective purchaser so that liability for the past
releases would not transfer to the new owner.
Comment 9: A commenter asked about a well that could not be sampled due to a dead
animal.
Response 9: Apparently a small rodent got trapped in the well, and the samplers could
not remove it, so the well could not be sampled.
Comment 10:A commenter asked why Cooper was responsible, and not McGraw-
Edison.
Response 10:Cooper purchased McGraw-Edison, and therefore assumed liability.
Comment 11: A nearby restaurant owner asked about using a portion of the site for
expansion of his business' parking lot.
Response 11 :The EPA had evaluated the area to be used for this parking lot
expansion. Contamination had been identified in this general area in the
subsurface. Activities at the surface such as construction of a parking
area as was described, should not be a problem. Arrangements to
construct on the site should be made in advance with Cooper.
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GLOSSARY OF TERMS USED IN THIS DOCUMENT AND OTHER
ASSOCIATED DOCUMENTS
This glossary defines most technical terms used in relation to the McGraw-Edison
Site in this ROD Amendment. The terms and abbreviations contained in this glossary
are often defined in the context of hazardous waste management, and apply specifically
to work performed under the Superfund program. Therefore, these terms may have
other meanings when used in a different context.
Administrative Record (AR): The body of documents that "forms the basis" for
selection of a particular response at a site. For example, the AR for remedy selection
includes all documents that were "considered or relied upon" to select the response
action. An AR is available at or near every site to permit interested individuals to review
the documents and to allow meaningful public participation in the remedy selection
process. This requirement does not apply to other ARs such as those for deletion.
Alluvial: An area of sand, clay, or other similar material that has been gradually
deposited by moving water, such as along a river bed or the shore of a lake.
Aquifer: An underground layer of rock, sand, or gravel capable of storing water within
cracks and pore spaces or between grains. When water contained within an aquifer is
of sufficient quantity and quality, it can be tapped and used for drinking or other
purposes. The water contained in the aquifer is called ground water.
Background Levels: The amount or level of any constituent that occurs naturally in
soil, water, or air.
Backwashing: The process of causing a flow of fluid through a system in the reverse
direction of normal flow for the purpose of clearing or cleaning by removal of materials
present.
Bedrock: The layer of rock located below the overburden soils. Bedrock can be
unweathered (solid and unaltered), weathered (altered by water, exposure to the
elements), or fractured (altered by earth's movements). Aquifers can be found in
certain types of bedrock.
Borehole: A hole drilled into the ground used to sample soil and ground water.
Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA): A Federal law passed in 1980 and modified in 1986 by the Superfund
Amendments and Reauthorization Act (SARA). The acts created a special tax that
goes into a Trust Fund, commonly known as Superfund, to investigate and clean up
abandoned or uncontrolled hazardous waste sites. Under the program, EPA can either:
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1) pay for site clean up when parties responsible for the contamination cannot be
located or are unwilling or unable to perform the work; or, 2) take legal action to force
parties responsible for site contamination to clean up the site or pay back the Federal
Government the cost of the clean up.
Consent Decree: A legal document, approved and issued by a judge, formalizing an
agreement between EPA and the potentially responsible parties (PRPs). The consent
decree describes clean up actions that the PRPs are required to perform and/or the
costs incurred and/or will be incurred by the government that the PRPs will reimburse,
as well as the roles, responsibilities, and enforcement options that the government may
exercise in the event of non-compliance by PRPs. If a settlement between EPA and
the PRPs includes clean up actions, jt must be in the form of a consent decree. A
consent decree is subject to a public comment period.
Containment: The process of enclosing or containing hazardous substances to
prevent the migration of contaminants into the environment.
Contaminants of Concern (COCs): Contaminants, identified during the site
investigations and risk assessments, that pose a potential risk because of their toxicity
and potential routes of exposure to public health and the environment.
Downgradient: Downstream from the flow of ground water. The term refers to ground
water flow in the same way that it does to a river's flow.
Downgradient/Down Slope: A downward hydrologic slope that causes ground water
to move toward lower elevations. Therefore, wells downgradient of a contaminated
ground water source are prone to receiving pollutants.
Effluent: Wastewater, treated or untreated, that flows out of a treatment plant, sewer,
or industrial outfall. Generally refers to wastes discharged into surface waters.
Explanation of Significant Differences (ESD): A document regarding a significant
change to the Record of Decision (ROD) when new information is discovered about a
site or difficulties are encountered during the remedial design/remedial action phase of
the clean up. An ESD is submitted into the Administrative Record to inform the public
of any significant changes that are made to the selected remedy.
Ex-situ: Contaminants taken from the ground and remediated.
Generator: A facility that "generates" hazardous wastes.
Ground Water: Water, filling spaces between soil, sand, rock, and gravel particles
beneath the earth's surface, that often serves as a source of drinking water.
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Hot Spot: An area or vicinity of a site containing exceptionally high levels of
contamination.
Hydrofacturing: The process of forcing fluids into tight soils to wedge and propagate
hydraulic fractures into the soil so that desired fluids will be allowed to flow in.
Hydrogeology: The geology of ground water, with particular emphasis on the
chemistry and movement of water.
Influent: Water, wastewater, or other liquid flowing into a reservoir, basin, or treatment
plant.
Institutional Controls: Controls placed on property to restrict access and (future)
development.
In-situ: Contaminant remediated in the ground (in place).
Landfill: A disposal facility where waste is placed in or on land.
Maximum Contaminant Levels (MCLs): The maximum permissible level of a
contaminant in water that is or may be consumed as drinking water. These levels are
determined by EPA and are applicable to all public water supplies.
Mitigation: Actions taken to improve site conditions by limiting, reducing, or controlling
toxicity and contamination sources.
Monitoring Wells: Special wells installed at specific locations on or off a hazardous
waste site where ground water can be sampled at selected depths and studied to
determine such things as the direction in which the ground water flows and the types
and concentrations of contaminants present.
National Oil and Hazardous Substances Pollution Contingency Plan (NCP): The
Federal regulation that guides the Superfund program.
Present Worth: The amount of money necessary to secure the promise of future
payment or series of payments at an assumed interest rate.
Operation and Maintenance (O&M): Activities conducted at a site after response
actions occur to ensure that the clean up or containment system continues to be
effective.
Organic Compounds: Chemical compounds composed primarily of carbon and
hydrogen including materials such as oils, pesticides, and solvents.
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Permeability: The ability of a substance to allow liquids or gases to pass through due
to interconnected pores within the substance.
Plume: A body of contaminated ground water flowing from a specific source. The
movement of the ground water is influenced by such factors as local ground water flow
patterns, the character of the aquifer in which ground water is contained, and the
density of contaminants.
Potentially Responsibilities Parties (PRPs): Parties, including owners, who may
have contributed to the contamination at a Superfund site and may be liable for costs of
response actions. Parties are considered PRPs until they admit liability or a court
makes a determination of liability. This means that PRPs may sign a consent decree or
administrative order on consent (see Consent Decree and Administrative Order on
Consent herein) to participate in site clean up activity without admitting liability.
Reasonable Maximum Human Exposure (RME): Risk-based concentrations
corresponding to an excess cancer risk of 1 in 1,000,000 (1e-6) or a hazard index of 1.0
(which ever is higher) for a reasonable maximum exposed resident.
Remedial Alternatives: The technology, or combination of technologies, used by EPA
in treating, containing, or controlling contamination at a Superfund site. A remedial
alternative usually addresses site-wide contamination.
Remedial Investigation/Feasibility Study (RI/FS): A two-part study that determines
the nature and extent of the problem presented by the release and evaluates the
options available for remedial action. The Remedial Investigation (Rl) emphasizes data
collection and site characterization and is typically performed concurrently with the
Feasibility Study (FS report). The FS report emphasizes data analysis in conjunction
with technologies available for consideration as remedial alternatives.
Remedial: A course of study combined with actions to correct site contamination
problems through identifying the nature and extent of clean up strategies under the
Superfund program.
Resource Conservation and Recovery Act (RCRA): RCRA is a Federal law that
regulates the transportation, storage, treatment, and disposal of hazardous wastes.
The requirements for a RCRA landfill include protective liners and a leachate collection
system.
Record of Decision (ROD): The official Agency document that explains which
remedial clean up alternatives have been considered, the selected remedy, technical
background relative to the decision, and how the decision complies with the law.
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Toxicity: A measure of the degree to which a substance is harmful to human and
animal life.
Unilateral Administrative Order (UAO): A legally binding order issued by EPA and
authorized by CERCLA section 106 in which EPA requires a PRP(s) to undertake a
response action. There must be imminent and substantial endangerment to the public
health or the environment before such an order can be issued.
Upgradient: This term refers to the direction of ground water flow in the same way that
the term upstream refers to a river's flow.
Upgradient/Upslope: Upstream; an upward slope. Demarks areas that are higher
than contaminated areas and, therefore, are not prone to contamination by the
movement of polluted ground water.
Vadose Zone: The unsaturated portion of soil between the ground surface and the
water table.
Volatile Organic Compounds (VOCs): VOCs are made as secondary
petrochemicals. They include light alcohols, acetone, trichloroethylene,
perchloroethylene, dichloroethylene, benzene, vinyl chloride, toluene, and methylene
chloride. These potentially toxic chemicals are used as solvents, degreasers, paint
thinners, and fuels. Because of their volatile nature, they readily evaporate into the air
increasing the potential exposure to humans. These compounds typically have low
water solubility, environmental persistence, and wide spread industrial use.
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N
C 1fBI by Rtftd UcNalty A Company AH nghta r*««rvod
FIGURE 1
SITE LOCATION MAP
SOURCEl CO(OCR SIERRA HcCRAH-EOISON SITE
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urn KNCE
RMM( OJUOB
SCALE IN FEET
160
320
soiwcci eotrifR sis»»»
FIGURE 2
SITE MAP
McfJHAW-rnfSnN CUF
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P-05«
P-.09 PeOS
P-06 • VsB-SC-2^
P-01
P-07 ¦
MVV- 19WT m P-04
P-02 • #
PLAN OF SOUTH CULVERT AREA
1020
1010
1000
I 990
9S0
970
U=fSPND
-o CHAIN LINK FENCE
P-03 • SOIL BORWC/SOUTH CULVERT SAMPLE LOCATIONS
3 TCE CONCENTRATION IN SOIL DEPTH ZONE^g/kg)
3 (FROU FIELD CC) NO-NON DETECT
NO SAMPLE TAKEN IN THIS DEPTH ZONE
;; WT TOP OF WATER TABLE BORING
SOIL BORING/SOUTH CULVERT SAMPLE LOCATIONS
r- 1020
L 970
HORIZONTAL SCALE IN FED
VERTICAL SCALE
EXAGGERATED 4X
SOURCE! MMR INC.
tcecocentrrtion
N SOILS IN THE SOUTH
CULVERT AREA (HAY 19881
McCRftM-COISON SITE
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SOURCEl NMB INC.
FIBURE 1
'' ~ WER TCE
AATI0N8 SITE HIDE
IMi? 19981
ncMam-COISM site
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N
—-\D
a
k£9BIL
* CHMM UNK rCMCt
e s&£«s&'
e> cnwcnoH mi
$ R fDMDl
r Httisi uowionws mm mm mu QO * *"* «»•/*>
M0IK ga nouic J n* iflanxw v nt mmm e»-« u» «•- <* ("" »••»)
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0Mt, ,s MltMPWCM LOCAHOH
'4Q— meum «n it* cotconwtiiw axiom (»»A)
g» u O "" "
SCALE IN FEET
160
320
IM-t XMDKD m MKCHtO MIU !«a 0»» POM
nor in w* wmnuM
FIGURE 8
LOCATION OF PR0P0SE0
IRON REACTIVE PERMEABLE
BARRIER
HcCRAH-EDISON sitc
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31 GftOUNOWAtEK ttvct 0*»* ( «** y *»»•>
df BORING ItRMiNAltD
g monjioring wcti scwcn
40 80
vi m CM 5C*t
CKACCCRAfCD «>
SOURCE: HWR INC.
FIGURE 9
IRON REACTIVE
PERMEABLE BARRIER
CROSS SECTION A-A'
McGRAW EDISON SITE
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V .1
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